A, B and C are the events that will cause an ecological disturbance.
Rationale:
A. Introduction of a new species: When a new specie is introduced, it increases the competition in ecosystem with the native species for food, water, space and shelter. This affects the reproductive success of the native species and thus the dynamics of ecosystem.
B. Climate change: Climate change is different from a simple change of weather. The best example would be of Antarctica where the ice is melting fast due to the global warming. The native species find it harder to adapt to the warm temperatures.
C. Late spring snowstorm: Spring is the season where the plants grow and animals shed their fur. When snowstorms occur in this season they harm these plants and animals that live there.
Answer:
recombinant DNA
A strand of DNA formed by splicing DNA from 2 different organisms is called recombinant DNA
Explanation:
Using the techniques of recombinant DNA technology, certain enzymes known as restriction enzymes capable of cleaving double stranded DNA in the plasmid of bacteria genomes (other organisms like eukaryotes can also be used) are used to obtain specific sequences of DNA bearing desirable traits in the both organisms.
Once the two DNA fragments have been obtained, another enzyme known as DNA ligase is used to seal the point of splicing, thereby constructing a single DNA from the two organisms.
This single DNA is known as Recombinant DNA
The answer is, d. consists of circular DNA molecule . The circular DNA is found in bacterias and archeas (which are prokaryotic organisms). The picture shows bacterial chromosome.